1. Field of the Invention
This invention relates to a sulfur containing molybdenum dihydrocarbyldithiocarbamate compound which is useful as an additive for lubricants.
Furthermore, this invention relates to a method producing such compound, and to a lubricating composition containing such compound.
2. Description of the Prior Art
In the field of this invention some prior arts are known. One of them is the description of Japanese Pat. Publication No. 24562/1970 and almost the same description as that is found in Japanese Pat. Publication No. 6362/1974 (those correspond to U.S. Pat. No. 3,356,702). Those Publications teach a method of producing the compound having the general formula [R.sub.2 N-CS.sub.2 ].sub.2 -Mo.sub.2 O.sub.m S.sub.(4-m) wherein R is a hydrocarbyl group and m is a number of 2.35 - 3, which compound is useful as an additive for lubricants. But that compound has insufficient lubricating properties, insufficient properties under extreme pressure conditions and insufficient anti-oxidation properties. The compound according to this invention cannot be obtained by the method described in those Publications.
Japanese Pat. Laid-Open Application (not examined) No. 56202/1973 teaches a compound having the general formula [R.sub.2 N-CS.sub.2 ].sub.2 -Mo.sub.2 S.sub.4 wherein R is an alkyl group, which compound is useful as an additive for lubricants. But that compound has a corrosive action on copper-containing materials, so the use of that compound has been limited.
Other descriptions mentioned as prior art to this invention are set forth in H. Isoyama and T. Sakurai, TRIBOLOGY international August 1974, 151-160, T.Sakurai, H. Okabe and H. Isoyama, Bulletin of The Japan Petroleum Institute 13(2) November 1971, 243-249, and T. Sakurai and H. Isoyama, ibid 16(2) November 1974, 112-117. The compounds used in those descriptions are the same compounds as used in the above mentioned Japanese Patent Publications.